SCIN131 Week 2 Quiz, Complete questions and Answers summer 2021

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Released: Jun 25, 2021 11:55 PM Your quiz has been submitted successfully. 3 / 3 points `Which of the following statements is true as stated by the chemist Joseph proust? Question options: All atoms o... f a given element have a constant composition and are different than atoms of any other element. All samples of a given compound have the same proportions of their constituent elements. The nucleus is a dense region of positive charge that always contains protons and neutrons. Matter cannot be either created or destroyed in a chemical reaction. Hide Feedback this is the law of constant composition 0 / 3 points What is matter made up of at the most fundamental level? Question options: neutrons isotopes electrons atoms Hide Feedback All matter is composed of elements, and all elements are made of atoms; but matter occupies spaces and has mass. Revie 3 / 3 points How would you correctly write the atomic symbol of nitrogen? Question options:Ni Ng Nt N none of the above Hide Feedback Topic discussed in Chapter 3.6 See the periodic table. 3 / 3 points `The elements that touch the zig-zag line on the periodic table are known as Question options: metals nonmetals metalloids transition metals none of the above Hide Feedback Topic discussed in Chapter 3.6 See the periodic table. 3 / 3 points An atom of bromine-79 contains Question options: 34 protons and 35 electrons, only 44 protons, 44 electrons, and 35 neutrons79 protons, 79 electrons, and 35 neutrons 35 protons, 44 neutrons, 35 electrons 35 protons, 79 neutrons, and 35 electrons Hide Feedback Topic discussed in Chapter 2 3 / 3 points Rutherford's experiment with alpha particle scattering by gold foil established that: Question options: evenly distributed throughout an atom. 0 times heavier than electrons. of protons, neutrons, and electrons. negative charge. positive charge. `When oxygen forms an ion, it Question options: loses two neutrons loses two protons gains two electrons all of these none of theseView Feedback 3 / 3 points `When hydrogen is combusted with oxygen the product is water. If you produce 20 grams of water using 2 grams of hydrogen, how many grams of oxygen were needed for the reaction? Question options: 22 10 40 18 none of the above Hide Feedback Great! Energy concepts are discussed in Chapter 9.1. This is a specific heat capacity problem. 3 / 3 points If one of the following elements forms an ion, which would have a -1 charge? Question options: Mg O Ag Ne Br Hide Feedback Topic discussed in Chapter 24 / 4 points `That nasty rotten egg smell is not actually gaseous sulfur, but rather hydrogen sulfide, or more properly named hydrosulfuric acid. It is heavier than air, too, so it tends to stick around for a while to share its delectible aroma. One mole of this compound would contain: Question options: 2 moles of hydrogen. 2 moles of sulfur. 1 mole of hydrogen. 4 moles of oxygen. 4 moles of sulfur Hide Feedback Good. You have to know naming here, as well as using forumulas as a mole conversion factor. 4 / 4 points The observation that 4.0 g of hydrogen reacts with 32.0 g of oxygen to form a product with O:H mass ratio = 8:1, and 6.0 g of hydrogen reacts with 48.0 g of oxygen to form the same product with O/H mass ratio = 8:1 is evidence for the law of: Question options: mass conservation multiple proportions energy conservation constant composition Hide Feedback Great! Topic discussed in Chapter 2. 4 / 4 points`I recently went to the dentist for a procedure that required me to have laughing gas (nitrous oxide, or N2O). I specified that I wanted EXACTLY 1.000 x 1025 molecules of this gas delivered to me. If he was going to be my dentist, he had to prove to me he knew a little chemistry. How many grams would he have to deliver? Question options: 1.100 × 103 44.01 730.9 16.61 Hide Feedback Good. Topic discussed in Chapter 2 4 / 4 points Calculate the molar mass of (NH4)2SO4. Question options: 118.14 g/mol 114.11 g/mol 228.22 g/mol 63.09 g/mol 132.15 g/mol Hide Feedback Great work! Topic discussed in Chapter 2 4 / 4 points Magnesium sulfate is sold commercially as Epsom Salts. Epsom salts are commonly used in baths to help reduce stress and fatigue on the body. What is the molar mass for Magnesium Sulfate? Question options:144.62 g/mol 72.37 g/mol 120.37 g/mol 24.31 g/mol Hide Feedback Great! Topic discussed in Chapter 2.4. You need to know the formula, then add the atomic masses. 4 / 4 points `Suppose I lay before you 5.0 gram samples each of Sr, Zr, Co, and Te. Which of these samples would contain the smallest number of moles? Question options: Sr Zr Co Te They would all contain the same number of moles Hide Feedback Good. Topic discussed in Chapter 2 4 / 4 points `In 2009, the average American produced 37,919.5 pounds of carbon dioxide emissions. If there are 454 grams in a pound, how many molecules of carbon dioxide is this? Question options: 44.0 2.36 × 10291.14 × 1024 1.90 Hide Feedback Good. See section 6.3 4 / 4 points `If you look closely at the mineral case in Superman Returns, you can see a chemical name given for kryptonite--sodium lithium boron silicate hydroxide with fluorine. What's interesting is that a new mineral was discovered in Serbia in 2006, and it matches this chemical composition (minus the fluorine)! Maybe you saw it on the news. It has none of the properties of kryptonite as seen in the Superman comics/movies, however. Anyway this new mineral, Jadarite, a.k.a. kryptonite, has a formula of NaLiSiB3O7(OH). How many moles of boron are in 4.80 moles of kryptonite? Question options: 4.80 10.8 14.4 1.60 658.4 Hide Feedback Good. Topic discussed in Chapter 2 4 / 4 points What is the mass of 3.50 x 1024 Ti atoms? Question options: 47.9 g 5.81 g278 g 47.9 amu 5.81 amu Hide Feedback Great work! Topic discussed in Chapter 2 3 / 3 points For a system at constant pressure, 12,400 calories of heat are released. This quantity of heat is equivalent to Question options: 1.92 × 10-5 J 2.96 × 103 J 1.24 × 104 J 5.19 × 104 J Hide Feedback Topic discussed in Chapter 9.1 3 / 3 points `Aluminum has a specific heat capacity that is about twice that of iron. To balls of each metal, both with the same mass, and that have an initial temperature of 95 degrees C, are dropped into a completely insulated container that has the same mass of water but an initial temperature of 30 degrees C. When thermal equilibrium is finally achieved (i.e. temperatures are no longer changing), which of these statements will be true? Question options: Both balls will reach the same final temperature The iron ball will reach a higher final temperature than the aluminum ball.The aluminum ball will reach a higher final temperature than the iron ball. The difference in the final temperatures of the balls depends on the initial mass of the water. The difference in the final temperatures of the balls depends on the intial temperature of the water. Hide Feedback Good. Energy concepts are discussed in Chapter 9.1. This is a specific heat capacity problem. No calculation needed, just a 0 / 3 points The nutritional calorie (Cal) is equal to: Question options: 4.184 J. 1 mcal. 4.184 cal. 1 kcal. Hide Feedback Topic discussed in Chapter 9.1 3 / 3 points `A cube of copper and cube of zinc that have the same mass and same initial temperature have a certain amounf of heat (Q) removed from them. The final temperatures are different. What property causes this difference? Question options: density heat of vaporization specific heat capacity volumenone of the above Hide Feedback Good. Energy concepts are discussed in Chapter 9.1. This is a specific heat capacity problem. No calculation needed, just a 3 / 3 points As ice cools from 273 K to 263 K, the average kinetic energy of its molecules will: Question options: decrease increase none of these remain the same Hide Feedback Great! Energy concepts are discussed in Chapter 9.1. This is a specific heat capacity problem. 3 / 3 points Which of the following is considered a secondary source of research? Question options: Theses compositions Conference papers Lab notebooks Peer-reviewed journals Published books Hide Feedback Correct! Secondary research is considered original work that has been interpreted or evaluated by a second party.3 / 3 points Why did scientists put shrimp on a treadmill? Question options: To determine how fast crustaceans can run To measure free radicals affecting crustaceans To provide therapy to injured crustaceans To educate the public about pollution To compare data to human "stress tests" Hide Feedback Correct! Understanding how crustaceans are impacted by poor water quality caused by human contamination was the bas 3 / 3 points What should be included when generating scientific questions? Question options: The word "why" Moral values Personal preferences Predictions about outcomes Very broad topics Hide Feedback Correct! Scientific questions should be specific enough to help design a good hypothesis and should be based on facts, tes 4 / 4 points Design a positive ion with a charge of +2:Protons: __ Neutrons:__ Electrons:__ Element:__ Mass:__ Charge:__ Stable Nucleus: ☐ Yes ☐ No Protron: 4, Neutrons: 5, Electrons: 2, Mass: 9, Element: Baryllium Charge: +2, Stable Nucleus: Yes 4 / 4 points What Changes when you add a Proton? When you add Proton, the charge of the nucleus changes and the atom's atomic number changes. 5 / 5 points In 2-3 sentences, what was the overall purpose of the lab for this week? This week seemed a little tougher, Chemistry is like a different language to me. The lab website was helpful, i was able to add or subtract different chemicals and see how it effected the atom. You can also see the elements change when you add protons. The purpose was to teach us about how adding and subtracting neutrons can change an element, learning how to create and change elements and learning the mass number and stability of elements. Attempt Score: 94 / 100 - 94 % Overall Grade (highest attempt): 94 / 100 - 94 % [Show More]

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